German Auslegeschrift No. 1 158 800 decribes an automatic sewing machine having a sewing head including a rotary housing arranged at an arm and a rotatably received hook bearing. Both the hook bearing and the rotary housing are synchronously rotatable about a common axis which essentially corresponds to the longitudinal axis of the needle. The rotary housing and the hook bearing are driven by a control motor operably connected to sensors which are guided by a trace line corresponding to the profile of a stitch contour to be produced. The sewing head is displaceable in two axes at a constant velocity with respect to the stationary workpiece. The needle bar in conjunction with an associated presser foot are arranged in a frame and a needle feed movement is opposite of the displacement direction of the movable sewing head with respect to the stationary workpiece displaceable by means of an eccentric drive. Similarly, the hook cooperating with the needle, is displaceably received in the housing of the hook bearing and operably connected to an eccentric controlling the axial displacement of the hook. In order to achieve this, the shafts and the gears for the needle bar drive and the hook drive are axially displaceable constructed. Further, in the rotary housing there is arranged a thread take-up lever and a thread tensioner. The drives of both cannot easily be released due to the displaceable arrangement of the needle bar frame. By the rotatability of the rotary housing and the hook bearing, tangential needle feed movement with respect to the sewing direction of the seam at the individual point of stitching is provided so that no mentionable forces of displacement occur relative between the workpiece and the needle. This patent does not disclose a sewing head housing having a first drive connection for connecting a crank means to a jogging means and a second drive connection for connecting the crank means to a thread take-up means. Other distinctions will be apparent from reading the following detailed description.
U.S. Pat. No. 4,347,797 describes an automatic sewing machine including a sewing head and a feeding device for the workpiece to be stitched that generates both, a two axis relative movement and a rotating movement at the workpiece with respect to the stationary sewing head to provide a tangential movement each between the needle feed movement and the workpiece relative to the stitch row to be produced. However, because of its construction, it is possible only to sew certain sizes of workpieces, as the workpiece hanging over the supporting plate cannot be tilted about the sewing head exceeding a certain angle. Due to the fact that the total of all movements required for the so-called tangential sewing must be carried out by the workpiece, the individual plies of the latter to be stitched together are strongly exposed to forces of displacement with respect to each other. Furthermore, larger workpieces can only be rotated or tilted slowly resulting in an extension of the sewing cycle.